22 THE MICROSCOPE. Feb. 
double terminated, and often show calcites attached. 
Two slides should be made. One as opaque mount and 
one mounted in diluted glycerine, as a “rolling slide.”’ 
Stamped envelope, will enable any reader of this paper 
to secure enough for making such mounts. 
Regarding Crystals. 
T. O. REYNOLDS, M. D. 
KINGSTON, N. H. 
The article on Iodo-Sulphate of Quinine in the last 
issne of the Microscope, attracted my attention. I had 
had the same or similar directions from books a score of 
times and many scores of times had I, as carefully asa 
man well could, tried to obtain the so called Herapathite. 
I just could not doit. A good microscope, plenty of acces- 
sories, a good polarizing apparatus and some experience 
in crystalography, but no Herapathite, or no typical Lodo. 
Sulph. Quinine crystals. What was the matter ? 
If you want a slide or two that transcend the beauties 
of any rainbow, dissolve a little Santonine in boiling 
Canada balsam andcool slowly. Then the radiate colors, 
the nuclear centers, the brilliant irridescence, changing 
under the rotating nico] will be a feast. Sulfonal gives 
unique effects under differing treatment. Orystalized 
from cold (water) solution,from hot solution, from balsam 
hot, from chloroform balsam heated, from hot glycerne, 
all have their peculiarities, beautiful, enchanting, in- 
structive. 
White's Objects.—About five years ago you sent me a 
line of these specimens which I have mounted and esteem 
as about the most interesting and valuable part of quite a 
large collection of objects. I enclose two dollars for more 
to be selected from the list of numbers I enclose. 
C. M. Marvin, 
New York City. 
